From: Joerg Roedel Date: Mon, 18 Apr 2011 13:45:46 +0000 (+0200) Subject: x86, gart: Make sure GART does not map physmem above 1TB X-Git-Url: http://git.alex.org.uk x86, gart: Make sure GART does not map physmem above 1TB BugLink: http://bugs.launchpad.net/bugs/775809 commit 665d3e2af83c8fbd149534db8f57d82fa6fa6753 upstream. The GART can only map physical memory below 1TB. Make sure the gart driver in the kernel does not try to map memory above 1TB. Signed-off-by: Joerg Roedel Link: http://lkml.kernel.org/r/1303134346-5805-5-git-send-email-joerg.roedel@amd.com Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman Signed-off-by: Tim Gardner --- diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index c01ffa5..197a46f 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -81,6 +81,9 @@ static u32 gart_unmapped_entry; #define AGPEXTERN #endif +/* GART can only remap to physical addresses < 1TB */ +#define GART_MAX_PHYS_ADDR (1ULL << 40) + /* backdoor interface to AGP driver */ AGPEXTERN int agp_memory_reserved; AGPEXTERN __u32 *agp_gatt_table; @@ -212,9 +215,13 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem, size_t size, int dir, unsigned long align_mask) { unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE); - unsigned long iommu_page = alloc_iommu(dev, npages, align_mask); + unsigned long iommu_page; int i; + if (unlikely(phys_mem + size > GART_MAX_PHYS_ADDR)) + return bad_dma_addr; + + iommu_page = alloc_iommu(dev, npages, align_mask); if (iommu_page == -1) { if (!nonforced_iommu(dev, phys_mem, size)) return phys_mem;